Maps are guides or drawings that help people locate something, find travel
directions, or understand an area. There are many kinds of maps
— road maps help us find our way; topographical maps show land
elevations; geological maps show the locations of natural resources;
relief maps show landforms; thematic maps show patterns such as population
density, climate, or vegetation. Topological maps show information
without regard to correct distances or geographic attributes.
Maps are generally presented with the north facing upwards, the south
facing downwards, the west facing toward the left, and the east facing
toward the right.
Maps use a system of longitude and latitude. Lines of latitude run
across the map and are called parallels. Lines of longitude, on the
other hand, run from the North Pole to the South Pole and are called
meridians. While each latitude line is parallel to every other
latitude line, no two lines of longitude are parallel to each other.
Instead, lines of longitude are about 70 miles apart at the equator.
From there they converge progressively until they come together at the two
The equator, whose latitude is zero degrees, divides the world into the
Northern Hemisphere and Southern Hemisphere. In contrast, the Prime
Meridian, which is at longitude zero degrees, divides the world into the
Western Hemisphere and the Eastern Hemisphere. The Prime Meridian
is an internationally established reference line that passes from north
to south through the Royal Greenwich Observatory in London, England.
How are lines of latitude and longitude numbered? Well, starting
from the equator, each degree of latitude, which is represented by a line,
is numbered to the north and to the south. These lines go as far as
the North Pole, at 90 degrees North latitude, and the South Pole, at 90
degrees South latitude. Lines of longitude are similarly numbered,
but eastward and westward to the 180th meridian — located on the
opposite side of the globe from the Prime Meridian.
When you combine latitude and longitude, you get a grid that geographers
call a graticule. The locations on a map are indicated by correctly
identifying the grid coordinates on the graticule. When naming the
coordinates, the latitude is given first, followed by the longitude.
When the latitude is referenced, it must be specified whether the location
is north or south of the equator. Similarly, when the longitude is
referenced, it must be specified whether the location is east or west of
the prime meridian.
In recent years, several mapping algorithms have been developed to chart
and describe the best routes to travel between geographic locations.
Taking into account such factors as distance, speed limits, and traffic
congestion, these sophisticated programs produce remarkably accurate
results for popular driving directions sites such as Mapquest, Google
Maps, Yahoo Maps, and Windows Live Local.
This site, MapsAndDirections.us, features a convenient directory of
online map and driving direction resources as well as United States and
World atlases. The scrollable state maps show cities and towns
as well as Interstate, Federal, and State highways; they can be printed
in sections and used as travel maps. The website also features an
overview of map projections, including four world map examples that
illustrate cylindrical and azimuthal projections.
This map portal features links to a wide range of world maps and United States map resources,
including community and political maps as well as environmental, health, and historical maps.
Learn where to purchase printed U.S. Government maps. www.USA.gov
Continental map and travel information about North America.
Learn about the physical features and demographics of the North American
continent, as well as its popular travel destinations. www.North-America-Map.com
Browse the maps and pictures of Canada and its provinces.
View the detailed road maps of each Canadian province and learn about
tourist destinations such as Niagara Falls and the Canadian Rockies. www.Canada-Maps.org